The purpose of the proposed studies is to examine the neural pathways underlying the conditioning of emotional meaning to sensory stimuli. In recent studies we have demonstrated that auditory emotional conditioning is mediated by pathways which diverge from the ascending auditory system subcortically, at the level of the medial geniculate nucleus. Our specific aims in this proposal are to: (a) demonstrate that the effects of lesions of the medial geniculate are due to disruption of auditory processing in the thalamus; (b) determine whether there is regional specialization within the acoustic thalamus in the mediation of auditory emotional conditioning; (c) identify the subcortical efferent projections of the medial geniculate nucleus; (d) examine the effects of lesions of areas projected to by the medial geniculate nucleus; (e) attempt to trace the auditory emotional conditioning pathway beyond the primary projections of the acoustic thalamus. To accomplish these objectives we shall use: (a) classical conditioning techniques to couple emotional responses to auditory stimuli; (b) neuroanatomical tracing (HRP and amino acid autoradiographic) techniques to identify possible conditioning pathways; and (c) select lesions along possible pathways to implicate specific areas in conditioning. Our long range objectives include: (a) variations in the behavioral paradigms used in order to begin to specify the functions of the various anatomical areas identified in the present proposal; (b) analysis of the neurotransmitters of identified pathways for the purpose of determining the role of neurotransmitters in auditory emotional conditioning. The information to be obtained from accomplishment of our immediate and long range objectives will contribute to our understanding of the brain mechanisms through which environmental events acquire emotional coloration. Progress in treating emotional disorders could be facilitated by such information.